Answer:
One could be in the cell. The cell respires, thus producing carbon dioxide in it. So the concentration builds up in the cell. Diffusion is the net movement of particles from a region of high concentration to a region of low concentration, and the carbon dioxide concentration outside the cell is less, therefore the carbon dioxide molecules moves outs of the cell.
Another scenario is when perfume is sprayed into the air. The perfume particles collides with the air particles (lower or no concentration of perfume). This process goes on and on. This is diffusion since the concentration perfume particles collides with the less concentrated particles of perfume.
You didn't put any answer choices, but air and water are generally the greatest.
pretty sure it is an ultrasound
B. answer is correct. HIV that causes AIDS has RNA instead of DNA.
HIV is actually a retro-virus.
Acquired immunodeficiency syndrome (AIDS) is a chronic, potentially life-threatening condition caused by the human immunodeficiency virus (HIV). By damaging your immune system, HIV interferes with your body's ability to fight the organisms that cause disease. The human immunodeficiency virus (HIV) is a lenti-virus (a subgroup of retrovirus) that causes HIV infection and over time acquired immunodeficiency syndrome (AIDS).